I have a 91 firebird that I put a tbi 350 in. Everything works expect the Speedo. It stays at zero. I read that it needs a buffer box so I got one out of a tbi roadmaster. I think I got it wired up correctly except for the vss wires as I can't find them in anywhere in the harness inside the car to splice them in to the buffer box. Does anyone know where they are on the harness by the ecm?

Thanks

 

What transmission did you swap into it? By that I mean, what vehicle did it come out of? I put a transmission out of a GMC Vandura and the speed sensor was the wrong type for my cluster and it wouldn't read. If it came from a Camaro/Firebird then someone else will be along to help with the wiring part of it.

 

I got the 700r4 from a late 80s camaro 5.0 tbi. Since then the transmission has crapped out. I just recently just installed a 700r4 from a 92 roadmaster. I haven't drove it yet to see if it works now but it probably doesn't.